A borescope is generally characterized as an elongated insertion tube which can be flexible with a viewing head at its distal or forward end. The borescope can also include a control housing at its proximal end for controlling or steering the forward end. Such a borescope has a bendable tube steering section or articulation section at the distal end adjacent to the viewing head. One or two pairs of control articulation cables extend through the articulation section and then through the remainder of the flexible insertion tube. These cables connect with a steering control in the control section. One or both pairs of these cables are differentially displaced to bend the articulation section. The viewing camera head assembly can thus be remotely oriented to facilitate the inspection of an object. Borescopes are intended for visual inspection of mechanical devices such as jet engines or turbines, where it would be difficult or impossible to examine the device's internal elements directly. If the borescope must be maneuvered into narrow tortuous passageways, the insertion tube must be flexible and must allow corresponding bending and steering. In addition, the pathway to the object can be quite long, and so it is often necessary that the borescope insertion tube be fifteen meters or more in length.
While several types of borescopes have been proposed, present borescopes have been observed to fail in specialized operating environments such as high temperature, high pressure, and liquid operating environments.
There is a need for a borescope adapted for use in specialized operating environments.